Twenty five years ago this week, protests at Tiananmen Square in Beijing ended in bloodshed. Hundreds died in the government crackdown. Thousands gathered in Hong Kong to mark the event and remember the victims, though no events were planned in China. -- (22 photos total)

A Chinese man stands alone to block a line of tanks heading east on Beijing's Changan Blvd. from Tiananmen Square in Beijing on June 5, 1989. A quarter century after the Communist Party's attack on demonstrations centered on Tiananmen Square on June 4, 1989, the ruling party prohibits public discussion and 1989 is banned from textbooks and Chinese websites. (Jeff Widener/Associated Press)

A quarter century after the Communist Partyís attack on demonstrations centered on Tiananmen Square on June 4, 1989, the ruling party prohibits public discussion and 1989 is banned from textbooks and Chinese websites. (Helene Franchineau/Associated Press) #

Three unidentified men flee the scene as a Chinese man, background left, stands alone to block a line of approaching tanks, background right, in Beijing's Tiananmen Square. The man in the background stood his ground and blocked the column of tanks when they came closer, an image captured on film by numerous other photographers and one that ultimately became a widely reproduced symbol of events there. (Terril Jones/Associated Press) #

A blood-covered protester holds a Chinese soldier's helmet following violent clashes with military forces during the 1989 pro-democracy demonstrations in Beijing's Tiananmen Square in this June 4, 1989 photo. (Shunsuke Akatsuka/Reuters) #

A rickshaw driver peddles wounded people, with the help of bystanders, to a nearby hospital in Beijing after they were injured during clashes with Chinese soldiers in Tiananmen Square. The crackdown ended a period of relative political openness, led to the downfall of Communist Party leader Zhao Ziyang and plunged Beijing into diplomatic isolation that lasted until the late 1990s. (Liu Heung Shing/Associated Press) #

In this combination of photos, a June 10, 1989 file photo, top, shows Peoples Liberation Army (PLA) troops standing guard with tanks in front of Tiananmen Gate, and almost 25 years later, a May 28, 2014 photo, bottom, shows Chinese paramilitary policemen marching through to clear tourists from the area for a flag-lowering ceremony on Tiananmen Square in Beijing. (Sadayuki Mikami, top, Alexander F. Yuan, bottom/Associated Press) #

A woman wears a T-shirt commemorating the 25th anniversary of the Tiananmen Square crackdown near Victoria Park a few hours before the annual vigil in Hong Kong, China, June 4. Hong Kong is the only place on Chinese soil where large scale events to commemorate the 047 June crackdown are held. (Jerome Favre/Associated Press) #

Zhang Xianling, whose son Wang Nan was killed by soldiers at the Tiananmen Square in 1989, holds his picture after journalists were turned away, at the window of her home in Beijing, April 24. As his 77-year-old mother, Zhang Xianling is under around-the-clock surveillance by eight police and security officers. Zhang said the level of scrutiny this year was unprecedented. As early as April, police officers barred foreign journalists, including Reuters reporters, from visiting her home. The extraordinary measures are explained by the fact that she is one of the co-founders of a group of families called the Tiananmen Mothers, who have long demanded justice for the victims of the massacre. (Petar Kujundzic/Reuters) #

People hold candles to commemorate China's 1989 Tiananmen Square events during a candlelight vigil in Hong Kong on June 4, 2014. Up to 200,000 people were set to take part in a candlelight vigil in Hong Kong on June 4 to commemorate the 25th anniversary of the bloody Tiananmen Square crackdown, as China seeks to wipe the incident from memory. (Philippe Lopez//AFP/Getty Images) #

Hong Kong police officers discuss their crowd control tactics as pro-democracy activists confront a pro-China group during a rally to mark the 1989 Tiananmen Square military crackdown, in Hong Kong on June 4. (Alex Ogle/AFP/Getty Images) #

A Chinese man rests on a street near Tiananmen Square in Beijing, China, June 4. Beijing put additional police on the streets and detained government critics Tuesday as part of a security crackdown on the eve of the 25th anniversary of the crushing of pro-democracy protests centered on the capital's Tiananmen Square. (Ng Han Guan/Associated Press) #

A general view shows participants holding candles during a vigil to commemorate the 25th anniversary of the Tiananmen Square crackdown in Hong Kong, China, June 4. Hong Kong is the only place on Chinese soil where large scale events to commemorate the 04 June crackdown are held. (EPA) #

A June 6, 1989 file photo, top, shows cyclists passing by slogans which read "Mobilize all citizens to crush martial law, protect Beijing," under a bridge where tanks are positioned on Changan Blvd., a road leading to Tiananmen Square, and almost 25 years later, in a May 29 2014 photo, bottom, a jeep full of armed Chinese paramilitary policemen patrol under the same bridge in Beijing. (Vincent Yu, top, Ng Han Guan, bottom/Associated Press) #

Sin Wai-keung, 52, newspaper editor and former news photographer, poses in front of a projection of a photograph he took in Beijing in 1989, in Hong Kong May 22. Sin's photo shows a man standing in front of a column of tanks in Beijing on the morning of June 5, 1989. Recalling the moment he took the photo, Sin said, "Most important, it got photographed. I didn't think about the danger, or whether it would become an iconic image, as the news was still going on." Sin further said, "I believe there will be more important images on June 4th to surface in the future which fully describe the event." (Bobby Yip /Reuters) #

A boy poses with a Chinese national flag in front of Tiananmen Square in Beijing June 4. From keeping foreign reporters off Beijing's Tiananmen Square to widespread censorship of the Internet, China marked 25 years since the bloody suppression of pro-democracy protests on Wednesday under a cloak of security. (Kim Kyung-Hoon/Reuters) #